Fire-alarm signal-boxes



F. LATTA.

Fire-Alarm Signal-Boxes. N0.134,552. Patentedlam7, 1873.

FINLEY LATTA, OF CINCINNATI, OHIO.

IMPROVEMENT IN FIRE-ALAR SlGNALBOXES.

Specication forming part of Letters Patent No. ld?, dated January 7,1873.

To all whom it may concern: Be it known that I, FINLEY LATTA, of Cinlcinnati, Hamilton county, Ohio, have invented an Improved Signal-Box forFire-Alarm Telegraphs, of which the followin gis a specification: Natureand Objects of the Invention. Signal-boxes nowin use are commonlyarranged so as to indicate the location of a fire by therotation of acircuit-w heel which is armed with a set of teeth or spurs thatcorrespond in number with that of the box from which the .the bell,where the signal is an audible one,

or, where registration is employed, to confuse one character withanother, thereby causing the pen of the instrument to record anunmeaning arrangement of dots and dashes, or else a continuous dash orscratch upon the paper. y

My invention belongs to the class of devices designed to remedy thisserious defect and to insurea prompt and yabsolutel y correct signal, nomatter how rapidly the operating-crank may be rotated. I accomplish thisdesirable result in the following manner: The rotating circuitwheel isdispensed with and a gravitating-bar substituted therefor, which bar hasthe signalcharacters arranged on one side of it. This signal-bar isrigidly attached to a piston or plunger which plays Vsnugly within acylinder p that depends from the bottom of the signal-box proper, andsaid piston is capable of being elevated within said cylinder andallowed to descendtherein, asy hereinafter more fully described. Thepiston has a small channel in it, through which the imprisoned airWithin the cylinder gradually and uniformly escapes during the descentof said piston, it being understood that the cylinder is open at top,(except as it is closed by the piston,) but closed at bottom. The signalor character bar may be ele-` vated either by a vertical-acting lifteror'handle or by the rotation of a crank in the usual manner; butwhateverdevice maybe employed for this purpose mustbe arranged iu such amanner as to leave the bar free to descend as soon as it has reached theutmost limit of its upward stroke, and not be arrested or other- Wiseinterfered with until the piston has reached the bottom of the cylinder.As the instrument records the characters only during the fall of thepiston, and as the latter is compelled to descend at a perfectly uniformand regular speed, it will be seen that there can be no possible chancefor a confusion of signals, although the operatin g crank or lifter bemanipulated with the greatest rapidity.

Description of the Accompanying Drawing.

Figure l is an elevation of a re-alarrnsignal-box embodying myimprovements, the operating devices being shown in their normalcondition and the door ofthe box thrown open. Fig. 2 is a verticalsection through the operative parts ofthe box, showing the position theyassume during the ascent of the piston or while an alarm is being turnedin. Fig. 3 is another vertical section through the box, showing thepiston in the act of descending. Fig. 4 is an elevation of a portion ofthe door of the box, lshowing the groove which the operating crank orVhandle traverses. Fig. 5 is a front elevation of the wheel whichelevates the character-rod, the shaft of said wheel with its accessoriesbeing shown in section. Fig. 6 is an edge view of said wheel and itsaccessories. Fig. 7 is a perspective view of the same wheel detachedfrom its shaft. Fig. 8 is an axial section through the wheel and itsaccessories, the door of the signal-box being closed;

and Fig. 9 is a longitudinal section of a portion of the character-bar.

Of the above illustrations, Figs. 7, 8, and 9 are drawn on an enlargedscale.

A represents a customary cast-iron box, to which is hinged, at a a', thedoor B that is maintained in a closed condition by a lock, b, orotherwise. Fitted to the lower end of this box is a tube or cylinder,C," which is open at top, but closed at bottom, as clearly shown inFigs. 2 and 3; and said cylinder is traversed by a plunger or piston,which is constructed as follows:v Securely clamped between two disks, DD', is a cupped leather or other suitable packing, a, which enables thepiston to move comparatively air-tight within the lcylinder' onits'descending` or effective strokes, and without sensible friction onits ascending or non-effective stroke. These three members, D D d, ofthe piston are traversed by a minute ap crture, E, which passescompletely through them, as shown in Fig. 2; and this aperturecommunicates wit-h al channel, f, inthe under side of a weight,-F, thatrests upon the piston.` This weight should be heavy enough to overcomethe friction of the piston within the cylf inder, and to compel thedescent of the former at any determined and uniform speed. Projectingfrom the piston is a rod, G, which is 'conli'ned toa vertical 'path byaguide, g, and said bar has inserted in it fillings g', of wood, Indiarubber, or other suitable non-conductor of electricity. These fillingscorrespond in .number and arrangement with the number of the signal tobe indicated from the box, which, in thepresent illustration, is 14, andthis numeral may be repeated twice on the character-bar, as represented,or it may be repeated three or more times, if desired. Attached to thecharacter-bar, near the lower end of the samefis a connecting-rod orpitma-n, H, whose .upper end takes hold of a wrist, t', that projectshorizontally from a lug, c', that radiates from the wheel I. This wheelor disk has a circumferential ange,j, which extends around vaboutone-half the periphery ot said wheel and .terminates in twoinwardly-projecting spurs,

K K', which are slotted at k k for a purpose whichwill be presently madeto appear. These vcam terminations permit the roller U to im- Ypingeagainst and leave the iiange J as gradually as possible, and thus avoidjarring. The rim of this wheel is recessed at Z to receive a tongue orspring, L, whose free end protrudes from the recess and is presentedtoward the front of the signal-box. The wheel I rotates freely upon ashaft, M, and it is prevented moving longitudinally of said shaft by thecoll-.lr m and thimhle N, the latter being secured to said shaft byset-screw n. Projecting from this thimble is an arm, O, that is Ycapable of a semi-rotation infront ofthe wheel I. Secured to the thimbleN is one end of a spiral or volute spring, P, whose other end isattached to a pin, p, that projects rearwardly from the bar Q, which isplaced transversely of the box A, and supports the wheel I and itsaccessories. Fitted in the bar Q is a bushing, q, which servesas ajournal-bearing for the shaft M. An outer collar, m', in connection withthe thimble N, prevents longitudinal movement of the shaft M within thebushing q. The exposed end ot shaft M terminates in a square head orarbor, m, that is adapted to enter the correspondingly-shaped socket 1of hub R, which latter is journaled horizontally within the door B ofthe box. The hub yR is rotated by a crank, T, Whose handle is loaded att, and said loaded portion traverses a groove, b', on the outside of thedoor, the groove being concentric with the axis of the hub. Pivoted to abracket, c, is a circuit- `two cups, to which are secured the twocustomary wires w w that project through the top of the box. The cup Whas also secured toit two wires, X x, of which the one X communicateswith a plate, u', below the long arm of the circuit-connector, while thewire m is attached to the magnet Y. Extending from the other magnet Y isa wire, y, which passes down to the arm o and thence to key Z. The othercup W has secured to it two wires, X x', the one X communicating withthe circuitconnector. The other wire m leads to the testing apparatus orkey Z. Projecting horizontally from the key Z is a pin, z, which limitsthe vibration of the long arm U ot the circiiitconnector. This connectoris maintained out of circuit77 by the spring u. Secured to the underside ot the bar Q is a stud, q", which' limits the distance to which themainsprin g I can rotate the arm O.

Operation.

My signal-box is operated in the following manner: In the normalcondition of the apparatus the door B is closed, the hub R engaged overthe arbor m ot' sha-ft M, and the weight t ot' the crank T rests at theleft end ot' groove b', the arm U ot' the connector being in contactwith the pin z. As soon as a lire occurs the person who is authorized toturn in the alarm7 has simply to rotate the crank T until the weight tcomes in contact with the right end ot' groove b', and then quit hishold of the crank, as the action ofthe instrument from this moment isentirely automatic. VThis movement ofthe crank causes a correspondingsemirotation of the shaft M with its attached thimble N and arm O. Assoon as the arm O begins to rotate it comes in contact with thespringtongue L, and thus compels the wheel I to turn in unison with saidshaft, thimble, and arm. Dnrin g the rotation of wheel I the pistonl) 1) d is bein g elevated through the instrumentality of connecting-rodH, and the leather cupping around the piston allows air to enter freelybelow it, so as to destroy the tendency to create a vacuum within thecylinder C. When the rotation of wheel I has brought its flange J incontact with the non-conducting roller u the arm Ul strikes against theplate u', thereby throwing the box out of circuit, and consequentlythere is no recording of signals while the bar G is being elevated. Thepositions which the various operative parts assume during the elevationof the piston is clearly seen in 2. YVhen the handle T reaches the limitof the groove b the wheel I will then have been rotated so fartoward theright as to carry the studi beyond the center of said wheel, andconsequently the weight F begins to act upon the latter in such a way asto continue its rotations. The wheel I having thus made a semi-rotation,the roller u escapes from under the flange J, and the spring a instantlyforces the arm Ul away from the plate a and against the pin z, therebythrowing the box in circuit, and consequently the proper signal isrecorded as the bar G passes down in contact with the linger V. As theimprisoned air within the cylinder C can escape only through the minuteaperture E, it will be seen that the descent of the piston iscorrespondingly gradual and uniform, and consequently there is no chancewhatever for the signals ever becoming confused with one another. Aspreviously stated, the operator quits his hold of the crank T as soon asit strikes the right end of groove b; and as this turning of said handlecaused a slight windin g up of the mainspring P, it will be seen thatthe moment the crank is free the tendency of said spring-to uncoilitself will instantly return the arm 0 to its normal position andmaintain it in contact with the stop q. But should the operatorinadvertently continue to operate the handlev during the action of thesignal, no motion will thereby be communicated to the wheel I, and thusall chances of an interfering signal is effectually guarded against.

The slots k la in the cam-shaped terminations K K of the circumferentialiiange J are for the purpose of allowing the free end of arm Q to sweepthrough said terminations without coming in contact with them. As suchcontact would cause an improper rotation of the wheel I the advantagesof the slots will be readily understood.

The` drawing represents only the internal portion of the signal-box; butit is to be understood that the parts represented are to be inclosedwithin an outer shell or case, in the usual manner.

Instead of the rigid pistou-rod herein represented, a iiexible band ofsteel or other suitable material may be attached at one end totheplunger D, the other end of said band being secured to asegment-wheel in such a manner that the descent of the piston will causethe characters upon the band to be brought in contact with the finger V.Or the piston-rod G may be geared toa signal-wheel having the usualcharacters upon it, as the gist of my invention consists in thegravitating-piston, whichis arranged so as to descend in a perfectlyuniform and gradualfananner, no matter whether said descent is regulatedby the compression of air, water, oil, or other fluid beneath it or byfriction merely. y

Useful novelty isl believed to exist in the rigid character-rodprojecting from a piston that traverses a vertical tuberor cylinder,open at top and closed at bottom, said piston being arranged so as to beelevated within the cylinder without sensible friction, and to have itsdescent within the same automatically retarded by the compression of airbeneath said piston.

I am aware that fire-alarm telegraph-boxes have been devised which havecomprised a gravitating motor or weight, which, after being oncestarted, has operated independently of the prime impulse, and that suchuniform action of such motor has been sought to be attained by means ofvarious horological expedients, such as escapements and springs; butsuch devices are believed to be objectionable by reason of theirexpense, consumption of power, and liability to deterioration. Itherefore make no claim, broadly, to such expedients.

Claims.

I claim as my invention- 1. In telegraph-lire-alarm signal-boxes, thecharacter bar or rod G brought into registering action by the descent ofa gravitating-piston, D Dl d, within a suitable tube or cylinder, C, thedescent of said piston being regulated substantially as herein describedand set forth.

2. The combination of the tube C', perforated piston D E, character-barG g' pitman H, wheel I i J K K 7c lc', spring Il, shaft M m, thimbleNin, arm O, operating-sprin g P, hub Rw', and crank T, as and for thepurpose specilied.

In testimony of which invention I hereunto set my hand.

' FINLEY LATTA.

Attest:A

GEO. H. KNIGHT, JAMES. H. LAYMAN.

